Good ICC printer profiles will give you the print that you want and expect. However, if what you get out of the printer isn’t what you wanted it can be hard to narrow down exactly what the problem is. This is because the printer is at the end of your workflow and it may not be the printer or its profile that is at fault. This blog will go through some basic evaluation and testing procedures that can be used when troubleshooting profiled print output. If you want information about the more specific problem of matching screen to print then read this blog.
Testing & Viewing
The first thing you need to do to test a printer profile is to remove the rest of your workflow from the equation. You need to test accuracy of the printer profile not your raw conversion, scanning or image editing. There are lots of specially designed test images on the net. I can send you mine on request. A good test form has a range of images and artificial tests to really put any profile through its paces. You should look for good neutrals and skin tones, even colour ramps and decent saturation.
The other thing you need to do is look at the prints in good viewing light. Normal artificial lights should be avoided at all costs. Use either daylight or a viewing booth that conforms to either the D50 or D65 standard. Poor lighting can lead you to think there are issues with your print when there are none. Daylight may vary with weather or time of day but it’s always got an good spread of wavelengths of light and is what most inks or toners are designed for.
Another thing you have to be aware of is your own expectations. People often assume that printer profiles should make everything match but a printer profile is just a measurement of what a combination of printer, ink and paper can reproduce. Different types of printers and ink sets will produce different colour gamuts. Different papers and surface textures will influence both colour gamut and appearance. Matte papers always look flatter than gloss papers for example. Also the colour of the paper white has a big influence. A warmer paper colour will give warmer greys and skin tones than a cooler more bluey white paper.
RGB Inkjet Printer Profiles
Inkjet printers that use a printer driver on your computer usually process data as RGB, and so are profiled as RGB devices. RGB Printer profile problems generally fall into two categories; errors in creation and errors in application. If you are printing to an inkjet through the manufacturer’s driver then there isn’t too much that can go wrong when you are making a profile, or getting one made for you by using a profiling service. You just need to print out the colour patches for the profiling software without any colour management. The easiest way to do this is to use Adobe Color Printer Utility, which is a free download from here.
You must also select an appropriate media type in the driver for your paper, and also ensure that no colour adjustment is selected in the Epson printer driver, application managed colours in a HP or colour correction none for Canon printers. Paper manufacturers should tell you what media type to use, or you can just experiment to see which gives you the best profile. If you download a profile from a paper manufacturer’s website then they should definitely tell you what media type to use, if they don’t then the profile is useless because the media type governs how much ink is used an a host of other variables.
Once you have a printer profile, either one you have created or downloaded you must stick to the media type that it was created with, and also no colour adjustment must still be selected in the driver. You must keep the driver settings identical to those used to output the profiling chart. The easiest way to do this is to save the settings as a printer preset. You need to apply the printer profile in the printing application. All of the Adobe Creative Suite products apply profiles really well, but many other application such as Microsoft products don’t allow you to use a printer profile at all. If you are printing from a none Adobe application it is always worth trying a print from Photoshop, for example, and comparing it to a print from the application you want to use. If the none Adobe product prints the same then you know the colour management is good. If it doesn’t then you know the profile isn’t at fault.
If you do get a print with a colour cast or other problem then the first step is to check that the printer profile has been applied correctly, and a suitable rendering intent used. You can use perceptual, saturation or relative colorimetric with black point compensation, and each will give slightly different results. So if you get a print you don’t like you can try a different intent. Make sure the driver settings are correct, with the right media type and no colour adjustment selected.
If you still don’t get a good result then check for physical printer issues such as clogged ink heads. Then consider if anything might have changed – have you changed ink supplier? Has the driver been updated? Printer profiles are fixed files; they never change. If you were printing fine one day but not the next then the printer, driver, software or file may be the problem. If you are certain that all the driver settings are correct and that the printer has no physical issues then the simplest fix may be to get a new profile made. My profiling service is cheap and quick, but I use top level software and hardware to make the profiles. Click here for more details.
CMYK Printer Profiles
Errors with RGB printer profiles tend to be in the application of the profile. With CMYK printer profiles of inkjets driven by a RIP or a toner based printer then the errors tend to lie more in the creation of the profile.
If your inkjet is driven by RIP software then part of the calibration and profiling process is setting the printer options, ink limiting and linearisation and it is with these that the root of most problems can be found. Getting the printer options right for any media can take a while, factors such as the number of passes, resolution, head height and drying times all can have a big influence on the print. Again the media manufacturer should be able to guide you.
Ink limiting can be a real dark art. If you limit too much you reduce the colour gamut but if you limit too little then you end up with drying or over inking issues. If you have made a profile through a RIP and aren’t happy with the results then go back and start again and examine all the choices you made. The only two common errors with the actual ICC profile creation tend to be either the use of an inappropriate measurement device or problems with black generation settings. Some low resolution printers or unusual media such as translucent media or cloth may need a specialist instrument for accurate measurement. Your profiling software will give you choice of how neutral colours are made up. Greys can be made up using cyan, magenta and yellow or black inks. Some printers produce best results using lots of black ink and less colours, other printers give better looking prints using more CMY.
One factor that users often neglect with RIPs is that profiles work in pairs and that the source profiles set in the RIP are often nearly as important for good output as the destination profiles. Setting better source profiles than the default ones used in many RIPs can improve your prints.
Laser Printers & Copiers
The most common problem with any toner based printer is consistency. Laser printers have many moving parts that can be subject to wear and can be heavily influenced by changes in humidity. One simple test I run on any laser printer before profiling is to print a series on flat colours across the whole page. If a printer is going to be successfully profiled the print needs to be consistent across the page, any variation across either axis is going to cause profile errors and make it difficult to judge the final output. Even when successfully profiled laser printers can vary quickly over time so always print out a test image after profiling and then reprint it if you suspect the printer has changed. If you compare the prints and there is a difference then if all the software settings are the same then it can only be a physical change in the printer that has caused the shift so it is time to recalibrate or reprofile.
This blog has skimmed over the main issues that can occur with printer profiles. If you have more specific issues then please comment or contact me and I will hopefully be able to point you in the right direction.